Details of delusional parasitosis vary among sufferers, but it is most commonly described as involving perceived parasites crawling upon or burrowing into the skin, sometimes accompanied by an actual physical sensation (known as formication). Sufferers may injure themselves in attempts to be rid of the parasites.
Perhaps one of the earliest trials in 1982, gave participants a dose of THC (1 mg/kg), followed by either a dose of valium or of CBD (0.5 mg/kg). The results suggested that CBD had a counteractive effect on THC stimulated anxiety.
Here, the medication doses were high. In adults, the standard Zoloft dose for depression is 50 mg daily. A number of patients in my practice have done well on 25 mg. To treat anxiety, the starting doses tend to be low; at first, antidepressants can increase anxiety. But for unknown reasons, the final dose, to mitigate anxiety, can be substantial.